Modified lignosulfonates as additives in oil recovery processes involving chemical recovery agents

Abstract

A process for producing petroleum from subterranean formations is disclosed wherein production from the formation is obtained by driving a fluid from an injection well to a production well. The process involves injecting via the injection well into the formation an aqueous solution of modified lignosulfonate salt as a sacrificial agent to inhibit the deposition of surfactant and/or polymer on the reservoir matrix. The process may best be carried out by injecting the modified lignosulfonates into the formation through the injection well mixed with either a polymer, a surfactant solution and/or a micellar dispersion. This mixture would then be followed by a drive fluid such as water to push the chemicals to the production well. The lignosulfonates may be modified by any combination of any two or more of: reaction with chloroacetic acid, reaction with carbon dioxide, addition of the methylene sulfonate radical to the lignosulfonate molecule and oxidation with oxygen.

1.  In a method for recovering oil from a subterranean formation containing oil and having an injection well and a production well wherein an aqueous surfactant solution is injected into the injection well in order to drive the oil to the production well wherein it is produced the improvement which comprises: injecting into the injection well in admixture with the surfactant solution lignosulfonates modified by oxidation with oxygen or ozone and sulfomethylation wherein the methylene sulfonate radical is added to the lignosulfonate wherein the lignosulfonates are present in an amount effective for reducing the extent of adsorption of the surfactant by the formation matrix.   
     
     
       2. In a method for recovering oil from a subterranean formation containing oil and having an injection well and a production well wherein an aqueous surfactant solution is injected into the injection well in order to drive the oil to the production well wherein it is produced the improvement which comprises: injecting into the injection well in admixture with the surfactant solution lignosulfonates modified by oxidation with oxygen or ozone and reaction with chloroacetic acid whereby said chloroacetic acid reacts with phenolic, hydroxyl and sulfonate groups in said lignosulfonates to yield carboxylate groups wherein the lignosulfonates are present in an amount effective for reducing the extent of adsorption of the surfactant by the formation matrix.   
     
     
       3. In a method for recovering oil from a subterranean formation containing oil and having an injection well and a production well wherein an aqueous surfactant solution is injected into the injection well in order to drive the oil to the production well wherein it is produced the improvement which comprises: injecting into the injection well in admixture with the surfactant solution lignosulfonates modified by sulfomethylation wherein the methylene sulfonate radical is added to the lignosulfonates and reaction with chloroacetic acid whereby said chloroacetic acid reacts with phenolic, hydroxyl and sulfonate groups in said lignosulfonates to yield carboxylate groups wherein the lignosulfonates are present in an amount effective for reducing the extent of adsorption of the surfactant by the formation matrix.   
     
     
       4. A method for recovering oil from a subterranean formation containing oil and having an injection well and a production well wherein flooding water is injected into the subterranean formation comprising: (a) injecting through the injection well into the formation an aqueous solution of lignosulfonates modified by oxidation with oxygen or ozone and sulfomethylation wherein the methylene sulfonate radical is added to the lignosulfonates wherein the lignosulfonates are present in an amount effective for reducing the extent of adsorption of the surfactant by the formation matrix,   (b) subsequently injecting into the formation via the injection well an aqueous surfactant solution also containing lignosulfonates in an amount as in (a) and modified as in (a) and   (c) producing oil from the formation via the production well.   
     
     
       5. A method for recovering oil from a subterranean formation containing oil and having an injection well and a production well wherein flooding water is injected into the subterranean formation comprising: (a) injecting through the injection well into the formation an aqueous solution of lignosulfonates modified by oxidation with oxygen or ozone and reaction with chloroacetic acid whereby said chloroacetic acid reacts with phenolic, hydroxyl and sulfonate groups in said lignosulfonates to yield carboxylate groups wherein the lignosulfonates are present in an amount effective for reducing the extent of adsorption of the surfactant by the formation matrix,   (b) subsequently injecting into the formation via the injection well an aqueous surfactant solution also containing lignosulfonates in an amount as in (a) and modified as in (a) and   (c) producing oil from the formation via the production well.   
     
     
       6. A method for recovering oil from a subterranean formation containing oil and having an injection well and a production well wherein flooding water is injected into the subterranean formation comprising: (a) injecting through the injection well into the formation an aqueous solution of lignosulfonates modified by sulfomethylation wherein the methylene sulfonate radical is added to the lignosulfonates and reaction with chloroacetic acid whereby said chloroacetic acid reacts with phenolic, hydroxyl and sulfonate groups in said lignosulfonates to yield carboxylate groups wherein the lignosulfonates are present in an amount effective for reducing the extent of adsorption of the surfactant by the formation matrix,   (b) subsequently injecting into the formation via the injection well an aqueous surfactant solution also containing lignosulfonates in an amount as in (a) and modified as in (a) and   (c) producing oil from the formation via the production well.   
     
     
       7. A method for recovering oil from a subterranean formation containing oil and having an injection well and a production well wherein flooding water is injected into the subterranean formation comprising: (a) injecting through the injection well into the formation an aqueous solution of lignosulfonates modified by oxidation with oxygen or ozone and sulfomethylation wherein the methylene sulfonate radical is added to the lignosulfonates wherein the lignosulfonates are present in an amount effective for reducing the extent of adsorption of the surfactant by the formation matrix,   (b) subsequently injecting into the formation via the injection well an aqueous surfactant solution and   (c) producing oil from the formation via the production well.   
     
     
       8. A method for recovering oil from a subterranean formation containing oil and having an injection well and a production well wherein flooding water is injected into the subterranean formation comprising: (a) injecting through the injection well into the formation an aqueous solution of lignosulfonates modified by oxidation with oxygen or ozone and reaction with chloroacetic acid whereby said chloroacetic reacts with phenolic, hydroxyl and sulfonate groups in said lignosulfonates to yield carboxylate groups wherein the lignosulfonates are present in an amount effective for reducing the extent of adsorption of the surfactant by the formation matrix,   (b) subsequently injecting into the formation via the injection well an aqueous sUrfactant solution and   (c) producing oil from the formation via the production well.   
     
     
       9. A method for recovering oil from a subterranean formation containing oil and having an injection well and a production well wherein flooding water is injected into the subterranean formation comprising: (a) injecting through the injection well into the formation an aqueous solution of lignosulfonates modified by sulfomethylation where the methylene sulfonate radical is added to the lignosulfonates in reaction with chloroacetic acid whereby said chloroacetic acid reacts with phenolic, hydroxyl and sulfonate groups in said lignosulfonates to yield carboxylate groups wherein the lignosulfonates are present in an amount effective for reducing the extent of adsorption of the surfactant by the formation matrix,   (b) subsequently injecting into the formation via the injection well an aqueous surfactant solution and   (c) producing oil from the formation via the production well.